Three.
A pattern.
He moved closer to the acoustic monitoring station.
“Chief, I want sonar to check the port side.”
“We already have contacts.”
“Not a contact. Close range.”
Lawson looked irritated.
“Cole, you’ve been awake how long?”
“Eighteen hours.”
“Exactly.”
Another series of knocks came.
This time the sailor who had laughed stopped smiling.
“You heard that?”
Lawson did.
His expression tightened.
Sonar began checking.
Nothing obvious appeared.
“No contact.”
Evan stared at the hull.
Then he remembered something from diving training years earlier.
Emergency tapping.
Divers trapped inside damaged structures sometimes used repeated patterns against metal.
But there shouldn’t be any divers here.
No exercise.
No friendly vessel nearby.
“Chief.”
“Don’t say it.”
“Someone could be outside.”
“At this depth?”
“I know.”
